Helleborus plant named ‘COSEH 810’

ABSTRACT

A new and distinct cultivar of  Helleborus  plant named ‘COSEH 810’, characterized by its upright and uniformly mounded plant habit; uniform and freely flowering habit; dark green-colored leaves; long flowering period; single light yellow green-colored flowers; and good garden performance.

Botanical designation: Helleborus niger×Helleborus lividus.

Cultivar denomination: ‘COSEH 810’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar ofHelleborus plant, botanically known as Helleborus niger×Helleboruslividus, and hereinafter referred to by the name ‘COSEH 810’.

The new Helleborus plant is a product of a planned breeding program inGlandorf, Germany. The objective of the breeding program was to createnew uniform Helleborus plants with unique and attractive plant habit,leaf and flower coloration and resistance to pests.

The new Helleborus plant originated from a cross-pollination conductedby the Inventor in Glandorf, Germany in November, 2003 of an unnamedproprietary seedling selection of Helleborus niger, not patented, as thefemale, or seed, parent with an unnamed proprietary seedling selectionof Helleborus lividus, not patented, as the male, or pollen, parent. Thenew Helleborus plant was discovered and selected by the Inventor as asingle flowering plant from within the progeny of the statedcross-pollination grown in a controlled greenhouse environment inGlandorf, Germany in February, 2006.

Asexual reproduction of the new Helleborus plant by divisions in acontrolled greenhouse environment in Glandorf, Germany since March,2006, has shown that the unique features of this new Helleborus plantare stable and reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

Plants of the new Helleborus have not been observed under all possibleenvironmental conditions and cultural practices. The phenotype may varysomewhat with variations in environmental conditions such as temperatureand light intensity without, however, any variance in genotype.

The following traits have been repeatedly observed and are determined tobe the unique characteristics of ‘COSEH 810’. These characteristics incombination distinguish ‘COSEH 810’ as a new and distinct Helleborusplant:

-   -   1. Upright and uniformly mounded plant habit.    -   2. Uniform and freely flowering habit.    -   3. Dark green-colored leaves.    -   4. Long flowering period.    -   5. Single light yellow green-colored flowers.    -   6. Good garden performance.

Compared to plants of the parent selections, plants of the newHelleborus are more uniformly mounded and are more uniformly and freelyflowering.

Plants of the new Helleborus can be compared to plants of Helleborusniger×Helleborus lividus ‘COSEH 700’, disclosed in U.S. Plant Pat. No.21,003. In side-by-side comparisons conducted in Glandorf, Germany,plants of the new Helleborus differed primarily from plants of ‘COSEH700’ in growth habit as plants of the new Helleborus were larger thanplants of COSEH 700′. In addition, plants of the new Helleborus and‘COSEH 700’ differed slightly in flower color.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying colored photographs illustrate the overall appearanceof the new Helleborus plant showing the colors as true as it isreasonably possible to obtain in colored reproductions of this type.Colors in the photographs may differ slightly from the color valuescited in the detailed botanical description which accurately describethe colors of the new Helleborus plant.

The photograph on the first sheet comprises a side perspective view of atypical flowering plant of ‘COSEH 810’ grown in a container.

The photograph on the second sheet is a close-up view of a typicalflowering plant of ‘COSEH 810’.

DETAILED BOTANICAL DESCRIPTION

The aforementioned photographs and following observations, measurementsand values describe plants grown in 15-cm containers during the winterin a glass-covered greenhouse in Glandorf, Germany and under conditionswhich closely approximate commercial Helleborus production. During theproduction of the plants, day temperatures ranged from 12° C. to 32° C.and night temperatures ranged from 3° C. to 18° C. Plants were 14 monthsold when the photographs and the description were taken. In thefollowing description, color references are made to The RoyalHorticultural Society Colour Chart, 2007 Edition, except where generalterms of ordinary dictionary significance are used.

-   Botanical classification: Helleborus niger×Helleborus lividus ‘COSEH    810’.-   Parentage:    -   -   Female, or seed, parent.—Unnamed proprietary seedling            selection of Helleborus niger, not patented.        -   Male, or pollen, parent.—Unnamed proprietary seedling            selection of Helleborus lividus, not patented.-   Propagation:    -   -   Type.—By tissue culture.        -   Time to initiate roots.—About two months at 12° C.        -   Time to produce a rooted young plant.—About six months at            4° C. to 15° C.        -   Root description.—Thick to thin, fleshy; white to brown in            color.        -   Rooting habit.—Sparse.-   Plant description:    -   -   Plant form and growth habit.—Herbaceous perennial; upright            and uniformly mounding plant habit with flowers held just            above the foliar plane; plant shape is globular; and            moderately vigorous growth habit.        -   Plant height.—About 37.1 cm.        -   Plant diameter (area of spread).—About 52 cm.-   Foliage description:    -   -   Arrangement.—Leaves arranged in a basal rosette; leaves            palmately compound with five leaflets per leaf.        -   Leaf length.—About 16.1 cm.        -   Leaf width.—About 17.1 cm.        -   Leaflet length.—About 10.3 cm.        -   Leaflet width.—About 4.5 cm.        -   Leaf shape.—Palmate; orbicular in outline.        -   Leaflet shape.—Elliptic to broadly elliptic.        -   Leaflet apex.—Acute.        -   Leaflet base.—Attenuate.        -   Leaflet margin.—Sharply serrate.        -   Leaflet texture, upper and lower surfaces.—Smooth, glabrous;            leathery.        -   Leaflet venation pattern.—Pinnate.        -   Leaflet color.—Developing leaves, upper surface: Close to            146A. Developing leaves, lower surface: Close to N199A.            Fully developed leaves, upper surface: Darker than between            N137A and 147A; venation, close to 143A; venation towards            the base, close to 200A. Fully developed leaves, lower            surface: Close to between N186C and 200A; venation, close to            N186C.        -   Petiole.—Length: About 16.3 cm. Diameter: About 5 mm.            Texture, upper and lower surfaces: Smooth, glabrous. Color,            upper and lower surfaces: Close to 144B; moderately to            heavily tinged and dotted with close to N186C.-   Flower description:    -   -   Flower shape and habit.—Single rotate flowers arranged in            terminal and axillary cymes; freely and uniform flowering            habit with about 65 flowers and flower buds per plant;            flowers facing outwardly to slightly nodding and slightly            upright.        -   Fragrance.—None detected.        -   Natural flowering season.—Plants begin flowering about ten            months after planting; long flowering period; plants flower            from late winter to early spring in Germany.        -   Flower longevity on the plant.—About ten days; flowers not            persistent.        -   Flower buds.—Length: About 2 cm. Diameter: About 1.2 cm.            Shape: Ovate. Color: Close to 145B to 145C; towards the            base, tinged with close to 177C to 177D.        -   Inflorescence height.—About 36.8 cm.        -   Inflorescence diameter.—About 13.8 cm.        -   Flower diameter.—About 6.5 cm.        -   Flower depth (height).—About 2.5 cm.        -   Petals.—Transformed into nectaries.        -   Sepals.—Quantity and arrangement: Five arranged in a single            whorl. Length: About 3.2 cm. Width: About 2.5 cm. Shape:            Broadly ovate to broadly elliptic. Apex: Rounded. Margin:            Entire. Texture, upper and lower surfaces: Smooth, glabrous.            Color: When opening, upper surface: Close to 145D; towards            the base, tinged with close to 182C to 182D. When opening,            lower surface: Close to 145C to 145D; towards the base,            tinged with close to 182C to 182D. Fully opened, upper            surface: Close to 145C; towards the base, close to 145A;            with development, color becoming closer to 147C shaded with            close to 176D and 177D. Fully opened, lower surface: Close            to 145C to 145D tinged with close to 182C to 182D.        -   Peduncles.—Strength: Moderately strong. Length: About            29.4 cm. Diameter: About 6 mm. Aspect: About 20° from            vertical. Texture: Smooth, glabrous. Color: Close to 145C            slightly dotted with close to 182C.        -   Pedicels.—Strength: Moderately strong. Length: About 2.9 cm.            Diameter: About 2 mm. Aspect: Erect to about 30° from the            peduncle axis. Texture: Smooth, glabrous. Color: Close to            148C.        -   Reproductive organs.—Stamens: Quantity per flower: About 60.            Filament length: About 1.6 cm. Filament color: Close to            157D. Anther shape: Reniform. Anther length: About 2 mm.            Anther color: Close to 150C. Pollen amount: Scarce. Pollen            color: Close to 158D. Pistils: Quantity per flower: About            six. Pistil length: About 1.2 cm. Stigma shape: Club-shaped.            Stigma color: Close to 157A. Style length: About 1.1 cm.            Style color: Close to 145C. Ovary color: Close to 145C.            Nectaries (transformed petals): Quantity per flower:            About 13. Length: About 8 mm. Diameter, apex: About 2 mm.            Diameter, base: About 1 mm. Shape: Flattened triangular.            Color: Close to 144B; towards the apex, close to N144B.        -   Seeds/fruits.—Seed and fruit development have not been            observed.-   Garden performance: Plants of the new Helleborus have been observed    to have good garden performance and to tolerate rain and wind.    Plants of the new Helleborus have been observed to tolerate high    temperatures of about 35° C. and are hardy to USDA Hardiness Zone 5.-   Pathogen/pest resistance: Plants of the new Helleborus have not been    shown to be resistant to pathogens and pests common to Helleborus.

1. A new and distinct Helleborus plant named ‘COSEH 810’ as illustratedand described.